(a) The rotors and blades must be mass balanced as necessary to—
(1) Prevent excessive vibration; and
(2) Prevent flutter at any speed up to the maximum forward speed.
(b) The structural integrity of the mass balance installation must be substantiated.
[Amdt. 27-2, 33 FR 963, Jan. 26, 1968]
source: Docket No. 5074, 29 FR 15695, Nov. 24, 1964, unless otherwise noted.
cite as: 14 CFR 27.659